Unverified Commit 76299a55 authored by Mario Limonciello's avatar Mario Limonciello Committed by Hamza Mahfooz
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drm: Introduce 'power saving policy' drm property 



The `power saving policy` DRM property is an optional property that
can be added to a connector by a driver.

This property is for compositors to indicate intent of policy of
whether a driver can use power saving features that may compromise
the experience intended by the compositor.

Acked-by: default avatarLeo Li <sunpeng.li@amd.com>
Signed-off-by: default avatarMario Limonciello <mario.limonciello@amd.com>
Signed-off-by: default avatarHamza Mahfooz <hamza.mahfooz@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240703051722.328-2-mario.limonciello@amd.com
parent 0e7f4e6a

drivers/gpu/drm/drm_connector.c

+48 −0
Original line number Diff line number Diff line
@@ -1043,6 +1043,11 @@ static const struct drm_prop_enum_list drm_scaling_mode_enum_list[] = { 
	{ DRM_MODE_SCALE_ASPECT, "Full aspect" },

};



static const struct drm_prop_enum_list drm_power_saving_policy_enum_list[] = {

	{ __builtin_ffs(DRM_MODE_REQUIRE_COLOR_ACCURACY) - 1, "Require color accuracy" },

	{ __builtin_ffs(DRM_MODE_REQUIRE_LOW_LATENCY) - 1, "Require low latency" },

};



static const struct drm_prop_enum_list drm_aspect_ratio_enum_list[] = {

	{ DRM_MODE_PICTURE_ASPECT_NONE, "Automatic" },

	{ DRM_MODE_PICTURE_ASPECT_4_3, "4:3" },
@@ -1629,6 +1634,16 @@ EXPORT_SYMBOL(drm_hdmi_connector_get_output_format_name); 
 *

 *	Drivers can set up these properties by calling

 *	drm_mode_create_tv_margin_properties().

 * power saving policy:

 *	This property is used to set the power saving policy for the connector.

 *	This property is populated with a bitmask of optional requirements set

 *	by the drm master for the drm driver to respect:

 *	- "Require color accuracy": Disable power saving features that will

 *	  affect color fidelity.

 *	  For example: Hardware assisted backlight modulation.

 *	- "Require low latency": Disable power saving features that will

 *	  affect latency.

 *	  For example: Panel self refresh (PSR)

 */



int drm_connector_create_standard_properties(struct drm_device *dev)
@@ -2131,6 +2146,39 @@ int drm_mode_create_scaling_mode_property(struct drm_device *dev) 
}

EXPORT_SYMBOL(drm_mode_create_scaling_mode_property);



/**

 * drm_mode_create_power_saving_policy_property - create power saving policy property

 * @dev: DRM device

 * @supported_policies: bitmask of supported power saving policies

 *

 * Called by a driver the first time it's needed, must be attached to desired

 * connectors.

 *

 * Returns: %0

 */

int drm_mode_create_power_saving_policy_property(struct drm_device *dev,

						 uint64_t supported_policies)

{

	struct drm_property *power_saving;



	if (dev->mode_config.power_saving_policy)

		return 0;

	WARN_ON((supported_policies & DRM_MODE_POWER_SAVING_POLICY_ALL) == 0);



	power_saving =

		drm_property_create_bitmask(dev, 0, "power saving policy",

					    drm_power_saving_policy_enum_list,

					    ARRAY_SIZE(drm_power_saving_policy_enum_list),

					    supported_policies);

	if (!power_saving)

		return -ENOMEM;



	dev->mode_config.power_saving_policy = power_saving;



	return 0;

}

EXPORT_SYMBOL(drm_mode_create_power_saving_policy_property);



/**

 * DOC: Variable refresh properties

 *

include/drm/drm_connector.h

+2 −0
Original line number Diff line number Diff line
@@ -2267,6 +2267,8 @@ int drm_mode_create_dp_colorspace_property(struct drm_connector *connector, 
					   u32 supported_colorspaces);

int drm_mode_create_content_type_property(struct drm_device *dev);

int drm_mode_create_suggested_offset_properties(struct drm_device *dev);

int drm_mode_create_power_saving_policy_property(struct drm_device *dev,

						 uint64_t supported_policies);



int drm_connector_set_path_property(struct drm_connector *connector,

				    const char *path);

include/drm/drm_mode_config.h

+5 −0
Original line number Diff line number Diff line
@@ -969,6 +969,11 @@ struct drm_mode_config { 
	 */

	struct drm_atomic_state *suspend_state;



	/**

	 * @power_saving_policy: bitmask for power saving policy requests.

	 */

	struct drm_property *power_saving_policy;



	const struct drm_mode_config_helper_funcs *helper_private;

};

include/uapi/drm/drm_mode.h

+7 −0
Original line number Diff line number Diff line
@@ -152,6 +152,13 @@ extern "C" { 
#define DRM_MODE_SCALE_CENTER		2 /* Centered, no scaling */

#define DRM_MODE_SCALE_ASPECT		3 /* Full screen, preserve aspect */



/* power saving policy options */

#define DRM_MODE_REQUIRE_COLOR_ACCURACY	BIT(0)	/* Compositor requires color accuracy */

#define DRM_MODE_REQUIRE_LOW_LATENCY	BIT(1)	/* Compositor requires low latency */



#define DRM_MODE_POWER_SAVING_POLICY_ALL	(DRM_MODE_REQUIRE_COLOR_ACCURACY |\

						 DRM_MODE_REQUIRE_LOW_LATENCY)



/* Dithering mode options */

#define DRM_MODE_DITHERING_OFF	0

#define DRM_MODE_DITHERING_ON	1